John f



Jan. 12 1926. 1,569,107

J. F. WHITE WATERPROOF PANEL BOARD Filed August 1.1, 1924' Patented Jan. 12 1926.

UNITED STATES JOHN I. WHITE, OF CHICAGO, ILLINOIS, ASSIGNOR TO WHITE PBODUCTSCOMPANY, OF

' CHICAGO, ILLINOIS, -A CORPORATION OF ILLINOIS.

wxmnrnoor PANEL 30am).

Application and Au ust 11, 1924. Serial No. 731,856.

To all whom it concern:

Be it known that I, JOHN F. WHITE, a

citizen of the United States, residing at- Chicago, in the county of Cook and State of Illinois, have invented certain new and use? ful Improvements in Waterproof Panel Boards, of which the following is a. specification.

The subject-matter of this invention is an improved article of manufacture in the nature of a panel board or the like suitable for various structural uses, such as in the interior sheathing for portions of automobiles, and comprises also a novel method for the manufacture of such an' article. Particularly in the automobile industry, but in many others as well, there are requirements for large quantities of boards or panels which may be purchased quite economically, and which have the proper stability and flexibility to withstand the shaping and the wear to which they are subjected, which are adapted to afford proper foundation for interior finish materials such as fabrics, imitation leather or the like, and which are effectively waterproof. Because of the great quantities of such material used, not only must production cost be considered, but also the expense of shipping and handling. Hence, it results that the matter of weight, packing and speed of production are of particular importance.

Heretofore various forms of waterproofed or water repellant sheet material have been made froin paper or other fibrous substances by various methods, such as the inclusion of waterproofing or water repellant materials in the pulp when thepaper or paper board is manufactured, the indurating of the sheets after their manufacture, and various coatings applied by dipping the sheets in a waterproofing material or spraying upon them to form a coating. While these various procedures lend themselves to quantity production in many instances, so far as I am aware, they all have rather serious drawbacks from the uestion of cost or the weight of the finis ed product, inconvemence in handling the dipped or coated material, and in many instances their loss of waterproof characteristics in certain particulars when shaped into panel boards or the like for the intended use.

The general purpose of the present invention is the provision of a structurally novel panel board in the nature of an article of manufacture which'may be produced at low cost, in large quantities of uniform quality, and will possess the requisite strength and flexibility, which is effectively waterproof,

PATENT OFFICE.

and which will hold a cement or glue for the mounting of a finishing fabric or the like.

An ancillary object is the provision of a melthod for the production of such an artic e.

Other purposes and advantages of the invention willbe pointed out hereinafter, indicated in the appended claims, or will be obvious to one skilled in the art upon an understanding of the resent disclosure.

For the purpose of t is ap lication I have illustrated in the drawing orming a art of this specification certain forms 1n w 'ch the invention may be embodied, and certain apparatus whereby the process maybe carried on, but it is understood that these are presented for illustrative purpose only, and are not to be accorded any interpretation regarded as imposing any limitations u on what I claim as my invention, short 0 its true and most comprehensive scope in. the art.

In the drawing, Fig. 1 is an elevational view of what I will designate a panel board, the same beingan article of manufacture suitable for use as an interior panel or interior sheathing for the door of an automobile body;

Fig. 2 is likewise a panel board ofan il- Fig. 4 is a diagrammatic illustration of apparatus which may be employed in practice of my new process, the same being in the nature of a longitudinalsectional elevation.

Quite a number of. different kinds of so called water-proof sheet material have been reduced which are suitable for the use or which the subject-matter of this invention is intended. So far as I am aware,

however, those which properly meet the require'ments are too expensive for use in the low necessary to cut notches for accommodationv of the hinges and cut holes for accommodation of the latch and the operating handle. While the general surface of the board may remain waterproof, it will be obvious that the edges where trimmed or shaped will lose their waterproof characteristics unless the sheet is thoroughly indurated or impllgegnated with the waterproofing material. asmuch as it is at such places that water is most likely to-reach the sheathing board, it will be apparent that this deficiency is a very serious one. In. boards which are thoroughly impregnated, various difliculties are encountered,- not only from relatively high manufacturing cost, but also from the cost of handling, shipment, etc. which is materially increased because of their considerably greater weight, due to the inclusion of so much more waterproofing material in them. Moreover, where it is sought to thoroughly impregnate the board, difficulties are encountered in getting the necessary amount of waterproofing material into the structure, because it must be considerably fluid, in order to get the "desired penetration, and in its diluted form a desired high concentration of the waterproofing material can not readily be obtained within the fiber of the article. On the other hand, coatings such as may be applied by dipping or spraying frequently do not accommodate the mouldmg or bending of the board, as is frequently necessary in shaping it to various applications, and the waterproofing coating may be marred or broken with comparative ease, and does not afford a good surface for taking cement or glue. Moreover the application of such coatings necessitates an appreciable time for drying, which slows up production and adds to manufacturin cost. 7

With t e subject-matter of the resent invention I have overcome the di culties mentioned above and have produced an effective waterproof panel board at extremely low cost. In brief, I accomplished this by employing in the first instance an ordinary paper board which is relatively inexpensive, shaping it to the desired form in which it is to be used and then giving it a heavy impregnation of waterproofing material on all exposed surface and edge portions, permitting the interior fiber to function as a drying aid by the absorption of excess liquid which in turn improves in certain respects the flexibility and coherence of the internal fiber. As a result, u n the re moval of the excess waterproo g material adhering to the surface, which may be accomplished ra idly by a mechanical operation, the board is delivered in such a condition that it may be stacked and packed for shipment immediately without requiring further time for drying. This leaves the board with its original surface texture, as distinguished from an oily, waxy or. applied surface such as vcontributed by the application of a surface coating, so that 1t is qualified to hold a cement or glue. The use of a tacky material, such as asphaltum, in the impregnating material also contributes to this result.

Described more in detail, by means of an illustrative instance, I may take the form of paper board now commercially known as container board, which is a relatively inexpensive product, and is in the nature of a composite structure having a chip center covered on both surfaces with a liner sheet of craft or relatively tough paper. means of suitable dies, or otherwise, I cut from such board the desired sha es, which I refer to herein as anels, in t e form in which they are used or applied to the intendedstructure, including in such shaping the formation of any interior apertures as well as the marginal irregularities. In the accompanying drawing the reference charactor 10 designates such panel boards, that illustrated in Fig. 1 being cut for an automobile door, and that illustrated in Fig. 2 a panel board such as cut for an instrument board front. In these illustrations the reference character 11 designates marginal notches and the reference character 14 designates various apertures within the marginal limits of the sheet, The ordinary container board has an appreciable grain, resulting from its construction, and it is referable in the shaping of the panel boar s to have the grain run in the major dimension of the panel. The panel boards, thus shaped for their intended'use, are then subjected to an application on all surfaces, of a waterproofing material in li uid form, such as ma be made by passing t e boards through a ath thereof. In Fig. t, let it be understood that the reference numeral 15 designates a tank containing the bath which is maintained in a heated condition, and the reference character 16 designates a conveyor made of very wide mesh -wire, which is arranged to be transmitted through the bath so as to carry the boards 10 through the latter. Upon removal from the bath the boards are passed between squeeze rollers 17 which remove surface excesses of the treating material.

As anappropriate mixture for the treating bath, take 50 ercent of-a petroleum distillate residuum with a melting point around 200 F., and

mix'with this, under heat, resin oil in the proportion of 20 percent, paraffin in the proportion of 15 percent, resin in the proportion of 15 percent, and thin the resulting mixture with a suitable lighter oil, such as mineral seal oil, which is advantageous because of its relatively high flash point. The proportion of light oil to be added to the mixture may be varied in accordance with the degree of penetration desired, and I have found it desirable to keep it as low as practicable. It is not desirable to subject the boards to extend soaking in the mixture, butthey should receive a suflicient application to permit it to thoroughly impregnate all sur ace portions. I have found a period of from one to three minutes to be practical and efiective, the bath being maintained at a temperature at or slightly above 212 F. This results in a heating of the board to a degree'at which surface drying is almost instantaneous after passing the board through s ueeze rolls to remove dripping excess. W ile it is not desired to impregnate the interior portions of the board, this treatment does result in the deep or complete impregnation of bruised portions or soft spots occasioned by insuflicient density or consolidation of the pulp in the board, thus giving the portions most susceptible to moisture a complete protection. The resulting structure is schematically illustrated in Fig. 3-, in which the reference character 18 designates the chip center portion of the board and the character 19* the craft surface portions. The shading is intended to illustrate the Waterproofing material in the fiber, and it will be observed that in all the edge portions of the sheet there is a quite substantial penetration and filling of the waterproofing material, while on the side surfaces the impregnation is much less extensive and in the interior there is substantially none. Consequently the absorptive interior draws into it the lighter and more fluid components leaving the surfaces substantially dry. Thus, it will be observed, the heavy and effective waterproofing constituents are disposed in the superficial portions where "they are most effective to resist the entrance of moisture, and the entire panel board is thus completely and effectively sealed against moisture on all surfaces both marginal and side, including the margins of all apertures. Thus complete rotection is secured by the addition of waterproofing material in an amount far below the total absorptive capacity of the board. As a consequence, there is very little, if any, increase in weight of the treated board over the untreated. Although therehas been an amount of waterproofing material incorporated into it, there has also been an extraction of a certain amount of the original water moisture of the board, due to the fact of the treatment under heat, and the weight of water moisture thus extracted compensates in a substantial measure for the weight of waterproofing material added. By keeping the proportion of paraffin low with respect to the relatively tacky materials such as the asphaltic residuum and the resin oil,'-the surface finish produced on the board, while dry, is very slightly tacky, rather than waxy, as a result of which it is particularly quali-' fied to hold glue or cement. Moreover it does not bleed or sweat out the waterproofing materials thus incorporated in it.

The boards thus formed and waterproofed, bein in condition for application to the inten ed structure without further shaping or trimming, thus retain their completely sealed and surface 'waterproot condition when assembled in the structure, and they lend themselves to curving to a substantial degree without creasing or breaking or destroying their surface waterproof characteristics. Their toughness is contributed to in a measure by the limited absorption of light oil constituents into the chip center portion, but without sacrifice, of their.

desired stability and their resistance to puncture is somewhat increased by the addition of the rather tenacious and coherent treating material in the surface portions.

Due to the rapidity with which the manufacture of the panel boards may be carried on, an important item in which is the elimination of any time for drying, and due to their comparative light weight, substantial reductions in first cost and cost of transportation are effected, as compared with fully impregnated boards. Another item of substantial saving is in the scrap. The scrap cut from, the untreated container board in shaping the panels, has an appreciable market value, as it may be utilized in the manufacture of similar board or other paper products. Scrap cut from treated board, however, does not have such market value and represents practically a total loss.

While in the illustrative embodimentabove described I refer to container board, it is to be understood that the invention is not limited to that particular material, as ply-wood or other absorptive sheet material may be used to produce an article embodying the invention. Theinstance given illustrates its utility in connection with a very inexpensive material. A

I claim:

1. An automobile panel board comprising a sheet of fibrous material having edges shaped for the intended structural use and having the fiber at all side and edge surface portions impregnated with water-repellent material, the sur-faces being free of unabsorbed oleagenous coatin and the interior fib'ers substantially devoid of the impregnating material.

2. A structural element consisting of a paper board comprising a chip center portion and tough surface liners sealed on all exposed surface portions by an impregnation of water-repellent material in the superficial fibers, the interior fibers being for the most part substantially free of such water-repellent material.

3. A panel board having a chip center and craft surface portions, with an impregnation of water-repellent material in the fibers toward the surface and the internal fibers substantially free of the water-repellent material.

4. The method of forming a panel board for structural use, comprising shaping a board of absorptive paper composition with the desired panel contour, and intra-marginal apertures appropriate to the intended use then applying a heated, tacky, waterrepellent liquid to all surfaces of the shaped panel in quantity sufiicient to impregnate the superficial fibers without impre nating the interior fibers, or leaving una sorbed excess of treating material on the surfaces. 5. A waterproofed board comprising a fibrous sheet having absor tive internal portions of chip material an surface liners of substantial "tensile strength, the surface fiber portions having an absorbed impregnation of water-repellent material of tacky nature without unabsorbed excess on the surface and the internal fibers being substantially free of the impregnating material.

In testimony whereof I have hereunto signed my name.

JOHN F. WHITE. 

